1. Field of the Invention
The invention relates to a developing frame, a process cartridge and an electrophotographic image forming apparatus.
Here, the electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium (such as, for example, recording paper, an OHP sheet or cloth) by the use of an electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (such as, for example, a laser printer or an LED printer), a facsimile apparatus, a word processor and a compound machine (such as a multifunction printer) of these.
Also, the term “process cartridge” refers to at least developing means as process means and an electrophotographic photosensitive drum integrally made into a cartridge which is detachably mountable on an electrophotographic image forming apparatus main body. Also, the term “developing frame” refers to joined frame members for holding members constituting a portion of the afore described developing means, such as, for example, a developer containing portion containing a developer therein, and a developing portion for developing an electrostatic latent image formed on the electrophotographic photosensitive drum by the use of the developer.
2. Related Background Art
Heretofore, in the electrophotographic image forming apparatus, there has been adopted a process cartridge system in which an electrophotographic photosensitive drum (hereinafter referred to as the “photosensitive drum”) and process means for acting on the photosensitive drum are integrally made into a cartridge, which is made detachably mountable on an image forming apparatus main body. According to this process cartridge system, the maintenance of the apparatus can be done by an operator himself without resort to a serviceman. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.
A construction shown in FIG. 20 of the accompanying drawings is known as the aforedescribed process cartridge (see U.S. Pat. No. 6,438,340).
As shown in FIG. 21 of the accompanying drawings, the welding of a toner developing frame member 101 and a toner developing wall member 102 is effected by a welding horn 133 for imparting ultrasonic vibration, and an anvil 134 when the welding horn 133 is brought into pressure contact. The toner developing frame member 101 and the toner developing wall member 102 are held so that surfaces 131 and 132 may get astride the anvil 134. The toner developing wall member 102 is brought into pressure contact while ultrasonic vibration is imparted thereto by the welding horn 133. Thereby, a welding rib is melted and the toner developing frame member 101 and the toner developing wall member 102 are welded together (see U.S. Pat. No. 6,438,340).
As shown in FIG. 20, a developer leakage seal for preventing the leakage of a developer from the end portions of a developing roller is stuck on the surfaces 131 and 132 by means of a two-side tape or the like. Thereafter, the developing roller is incorporated into a developing frame. By this developer leakage seal, the developer is prevented from leaking from the end portions of the developing roller.